Battery electric vehicles, extended-range electric vehicles, and hybrid electric vehicles all use a rechargeable high-voltage battery as an onboard source of electrical power for one or more traction motors. The traction motor(s) alternately draw power from and deliver power to the battery during vehicle operation. When the vehicle is propelled solely using electricity from the battery, the operating mode of the vehicle is typically referred to as an electric-only (EV) mode.
Vehicles that use torque from an internal combustion engine, whether for direct mechanical propulsion or to generate electricity for powering the traction motor(s) or charging the battery, may use an engine-driven fluid pump to circulate lubricating and/or cooling fluid to various powertrain components. Clutches, valve bodies, gear sets, and other wetted or fluidic components are thus provided with a reliable supply of fluid during engine-on transmission operating modes. However, an engine-driven main pump is not available in every transmission operating mode, such as when operating in an EV mode. Moreover, certain vehicle designs dispense of an engine-driven main pump altogether. Therefore, an electrically-actuated fluid pump may be used either as an auxiliary pump when an engine-driven main pump is present, or as the vehicle's sole fluid pump.